Selection of Acid Lactic Bacteria strains isolated from new born calves for the disign of a new probiotic product to be use as additive for prevention of diarrohea

MALDONADO NC, SILVA DE RUIZ C, SESMA F, NADER-MACÍAS ME

San Miguel deTucumán

Simposio; III Simposio Internacional de Bacterias Lácticas. Segundo encuentro de la Red Argentina de Bacterias Lácticas; 2009

CERELA-CONICET

The use of probiotics as Additives in Animal Feed is a promising alternative against antibiotics for the prevention of new born calves’ diarrhea. Probiotics additives improve health, weight gain and prevent gastrointestinal pathogens colonization. Furthermore, probiotics are considered GRAS (Generally Regarded as Safe) microorganisms and do not confer antibiotic resistances. The objective of our group is the design of a new probiotic product to be use as an Additive in Animal Feed. Fourteen Lactic Acid Bacteria (LAB) were selected from 96 strains isolated from new born calves. The samples were taken from feces and oral cavity; the isolated strains were screening by theirs surface properties (auto-aggregation and hydrophobic patterns) and production of inhibitory substance. The selected bacteria were identified by molecular techniques and incorporated to the CERELA Culture Collection. In the selected bacteria, functional properties, antibiotic susceptibility and compatibility between them were evaluated. Lately, the potential combinations of the strains were assayed, by using detection and enumeration of the strains by theirs antibiotic resistances profiles. The bacteria selected were Lactobacillus johnsonii CRL1699, CRL1701, CRL1692, CRL1700, CRL1693 and CRL1701 Lactobacillus amylovorus CRL1697 Lactobacillus murinus CRL 1695 and CRL1705, Lactobacillus mucosae CRL1698 and CRL1696, Lactobacillus salivarius CRL1694 and CRL1702 and Enterococcus faecium CRL1703. The strains were resistant to bile salts but were not able to grow at very lows pH. Different patters of antibiotic resistance were observed. Some of the selected bacteria inhibited the growth of Lb murinus CRL 1695. Finally, the combination of Lb mucosae, Lb salivarius, Lb amylovorius and E faecium was evaluated and the strains were identified by their antimicrobial resistance to vancomycin, ciprofloxacin, and riphampicine. The results obtained will contribute to further select the best combination of beneficial bacteria for the final design of a probiotic product. Technological properties of the selected strains and theirs combinations are also being evaluated. The design of a novel Probiotic Additive in Animal Feed for the prevention of new born calves’ diarrhea could be used to replace antibiotics and in this way to avoid the appearance of new resistant microorganisms.